PE1850 Linux install problem

[pzero]

Hi,
I got a new PE1850 with the integrated SCSI controller (PERC) and two 
internal hard disks in RAID 1 setup.

I put an LSI controller into the PE1850 and attached an Apple Xraid to it.

I am trying to install RH Enterprise Linux 3 ES U3 on the PE1850, using 
Linux PXE/HTTP install.

I can install it just fine, but I have problems with the GRUB boot loader.

The problem is that the Apple arrays are seen by Linux as 'sda' and 
'sdb', while the internal PE array is seen as 'sdc'.

In the Linux install process, I have the choice to install GRUB on the 
master boot record ('sda' - Apple Xraid) or on the first sector of the 
partition ('sdc1' - PE raid array).

I don't want to install the boot loader on the Apple Xraid, since I want 
to be able to boot the PE1850 even if the Xraid is down.

If I install the boot loader on 'sdc1', the system gets stuck in the 
boot stage with the error:
"GRUB Hard Disk Error"

Is there any way to revert that order and have the internal array appear 
to Linux as 'sda'?

Any other workaround to my problem?

Thanks a lot.